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[Corona ni Makeruna] Could Beppu Hot Spring Water Reduce Spread of COVID-19?

Researchers are looking into whether visiting the famous hot spring, or using special microorganisms found in its water in humidifiers and mouthwash, could help fight against the spread of COVID-19.





A microorganism in the hot spring water at the famous Beppu resort in Oita Prefecture shows promise for reducing the infection risk of COVID-19 by at least 53%, according to a specialist research institute.

Sarabio Onsen Probiotic Lab, which is based in the city of Beppu, made the discovery after looking into the matter. Their investigation suggests that the microorganism can enter the body not just by bathing in the Beppu hot springs and saunas but also via humidifiers and by gargling.

Sarabio plans to work with local authorities and press ahead with clinical trials and further experiments, with the aim of promoting the benefits of hot spring water in preventing the spread of COVID-19.

Sarabio Onsen Probiotic Lab

In 2011, Sarabio succeeded in isolating and cultivating an algae-related  microorganism that is present in hot spring water inside the company’s premises. The strain, which is known as “RG92,” was awarded a patent in 2015.

When people are under stress or have irregular lifestyles, their internal balance breaks down and their intestinal environment is negatively affected. Their immune system becomes weaker and mucosal cells can become inflamed. This can lead to an increase in the number of viral inducers, which in turn increases the risk of infection. 

However, Sarabio’s RG92 significantly reduces the increase in viral inducers by 53.4%, and it helps suppress inflammatory reactions. (The viral entry inducer, TMPRSS2, is a cell surface proteolytic enzyme that facilitates infection in human cells.)

Beppu Microorganisms

“If RG92’s suppression of viral inducers in the intestine can be verified in clinical trials, it should be possible to reduce the risk of COVID-19 infection by an equivalent amount,” explains Mitsuyoshi Miyata of Sarabio’s central research institute.

Sarabio has conducted joint research with Hiroshima University, Juntendo University, Kurume University, and Ritsumeikan Asia Pacific University. Their research programs confirmed that RG92 is effective in terms of inflammation control, oxidation, and anti-aging.

The team has also promoted the positive effect of RG92 concerning bruises, arthritis, atopic dermatitis, and metabolic syndrome at international conferences and in academic journals.


We want to work with Oita Prefecture, Beppu city, related organizations, and the tourist industry and further confirm the effectiveness of RG92 in tackling COVID-19 – with the additional goal of attracting tourists to Beppu’s hot springs,” says Sarabio executive Shigeru Hamada.

The company also plans to expand sales of products containing RG92 in both Japan and overseas, to promote the health benefits of this special microorganism. 

RELATED: Japan to Extend Stronger COVID-19 Restrictions to Tokyo, Kyoto to Deal with New Surge

Author: Masumi Kawasaki

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